Back in April, m.k., the original developer of these popular emulators, promised that support for MOGA controller was coming. Eight months later, m.k. has stopped developing for the Windows Phone 8 ecosystem. Fortunately, another developer picked up where m.k. stopped and today, MOGA controller support finally comes to all 3 emulators.
The feature is free in Snes8x and costs $0.99 in VBA8 and VGBC8. It is recommended that you have GDR3 but GDR2 may work as well. The developer urges you to test the feature in Snes8x before paying for it in VBA8/VGBC8. He also put up a couple of video tutorials on pairing the controller and using cheat codes. Watch them here:
MOGA controller tutorial
Cheat code tutorial